Urea as an Extender of Protein When Fed to Cattle

Abstract

Crystalline urea, DuPont's “Two-Sixty-Two” feed compound and pelleted feeds containing urea were used in a series of digestion trials and feeding experiments to determine the value of urea in extending the available supply of protein supplement for beef cattle. The pelleted feeds contained 10 percent blackstrap molasses, and varying amounts of hominy feed, cottonseed meal, and either crystalline urea or DuPont's “Two-SixtyTwo.” These supplements in which approximately 25 percent, 50 percent, 75 percent, or nearly 100 percent of the supplemental nitrogen has been furnished by urea, were fed with a basal ration of low grade prairie hay to yearling and two-year-old steers in metabolism stalls. When fed under such conditions, the pellets which did not carry more than 50% of their total supply of nitrogen from urea and the remainder largely from cottonseed meal, were similar to straight cottonseed meal in promoting nitrogen storage. Urea alone was a poor supplement to prairie hay. Pellets containing approximately 25 percent of their nitrogen as urea proved satisfactory as a source of supplemental nitrogen in two dry lot studies with fattening calves. Pellets containing 50 percent of their nitrogen as urea were a satisfactory supplement in the early phases of a fattening period, but proved unpalatable in the later phases. In two experiments, pellets containing approximately 25 percent of their nitrogen as urea have given as satisfactory performance as cottonseed meal when fed to yearling heifers on the range. In one test the pellets did not prove as satisfactory as cottonseed meal in wintering heavy steers under range conditions. No results indicating toxic effects of urea were obtained in these studies although urea was fed as a source of nitrogen at relatively high levels. Copyright © . .